Mobile Computing and Internet of Things 2019/20 fall

MainActivity.kt

package ee.ut.cs.lab11alpha

import android.os.Bundle
import android.util.Log
import androidx.appcompat.app.AppCompatActivity
import org.eclipse.paho.android.service.MqttAndroidClient
import org.eclipse.paho.client.mqttv3.IMqttDeliveryToken
import org.eclipse.paho.client.mqttv3.MqttCallbackExtended
import org.eclipse.paho.client.mqttv3.MqttMessage

class MainActivity : AppCompatActivity() {

    // 10.0.2.2 refers to host machine from Android emulator
    // If you are not using an emulator, you will have to specify a 'real' ip. See
    //https://developer.android.com/studio/run/emulator-networking.html for more
    private val MQTT_BROKER_IP = "tcp://10.0.2.2:1883"

    val TAG = "MqttActivity"

    lateinit var mqttClient: MqttAndroidClient


    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)


        // set up client
        mqttClient = MqttAndroidClient(this, MQTT_BROKER_IP, "lab11client")

        mqttClient.setCallback(object : MqttCallbackExtended {

            override fun connectComplete(reconnect: Boolean, serverURI: String?) {
                Log.i(TAG, "MQTT Connected")
                //TODO: subscribe to a topic
            }

            override fun messageArrived(topic: String?, message: MqttMessage?) {
                Log.i(TAG, "MQTT Message: $topic, msg: ${message.toString()}")
            }

            override fun connectionLost(cause: Throwable?) {
                Log.i(TAG, "MQTT Connection Lost!")
            }
            override fun deliveryComplete(token: IMqttDeliveryToken?) {
                Log.i(TAG, "MQTT Message Delivered!")
            }
        })

        mqttClient.connect()    //  Can also specify options, e.g. :  mqttClient.connect( MqttConnectOptions().apply { isAutomaticReconnect=true } )

    }

    override fun onDestroy() {
        mqttClient.disconnect()
        super.onDestroy()

    }
}